It’s rare for car owners to not show up at the meeting point. It’s possible that they’re delayed, especially if they’re picking you up at a stopover part-way through their journey, so we recommend you wait for 30 minutes. If they still don’t show up, call them to find out what has happened.
Please also let us know if you didn’t travel with the car owner. From your dashboard, go to “Bookings”, find the relevant booking, and confirm that you didn’t travel together.